Flame retardant for hydrocarbon diene rubbers

Abstract

Fire retarded compositions comprise elastomers derived from conjugated, hydrocarbon dienes in combination with a synergistic, three-component flame retardant system comprising (1) a chlorine- and/or bromine-containing fire-retardant additive, (2) alumina trihydrate and (3) an iron oxide.

What is claimed is: 
     
       1. A flame retarded elastomeric composition comprising: (a) a hydrocarbon conjugated diene elastomer wherein said diene elastomer consists of (1) at least one homopolymer of a hydrocarbon conjugated diene; (2) at least one copolymer of a hydrocarbon conjugated diene with at least one ethylenically unsaturated monomer selected from the group consisting of C 2  to C 12  hydrocarbon monomers, C 3  to C 8  carboxylic acids, esters of said acids with C 1  to C 8  alcohols, C 2  to C 8  halogen containing monomers and mixtures thereof; or mixtures of (1) and (2)   (b) about 5 to about 100 parts by weight per 100 parts by weight of said elastomer of a halogen containing organic compound wherein said compound consists of (1) at least one non-polymeric aliphatic, aromatic or alicylic compound having a halogen content of about 35% to about 85% by weight based on the compound, (2) at least one polymeric compound selected from the group consisting of polychloroprene, chlorinated polyethylene, chlorosulfonated polyethylene, epichlorohydrin polymers and copolymers, chlorinated polyvinyl chloride and polyvinylidene chloride or (3) mixtures thereof;   (c) about 10 to about 700 parts by weight per 100 parts by weight of said elastomer of alumina trihydrate; and   (d) about 0.5 to about 100 parts by weight per 100 parts by weight of said elastomer of an iron oxide which is selected from a group consisting of anhydrous ferric oxide, hydrated ferric oxide, anhydrous ferrosoferric oxide, hydrated ferrosoferric oxide or mixtures thereof.   
     
     
       2. The composition of claim 1 wherein the diene elastomer is (1) a homopolymer of a hydrocarbon conjugated diene; (2) a copolymer of a hydrocarbon conjugated diene and at least one ethylenically unsaturated monomer; or (3) mixtures thereof. 
     
     
       3. The composition of claim 2 wherein the diene elastomer is (1) natural rubber, (2) polybutadiene, (3) polyisoprene, (4) a copolymer of butadiene or isoprene or (5) mixtures thereof. 
     
     
       4. The composition of claim 2 wherein the hydrocarbon conjugated diene elastomer is styrene-butadiene rubber, natural rubber or a mixture thereof. 
     
     
       5. The composition of claim 1 or 4 wherein the halogen containing compound is a non-polymeric aliphatic, aromatic or alicyclic compound having a halogen content of about 35 to about 85% by weight based on the compound. 
     
     
       6. The composition of claim 1 or 4 wherein the halogen containing compound is a polymeric compound selected from the group consisting of polychloroprene, chlorinated polyethylene, chlorosulfonated polyethylene, polyvinylidene chloride and mixtures thereof. 
     
     
       7. The composition of claim 4 wherein the halogen containing compound is present at about 10 to about 85 parts by weight per 100 parts by weight of elastomer; the alumina trihydrate is present at about 10 to about 250 parts by weight per 100 parts by weight of elastomer and the iron oxide is present at about 2 to about 20 parts by weight per 100 parts by weight of elastomer. 
     
     
       8. The composition of claim 4 wherein the halogen containing compound is present at about 15 to about 70 parts by weight per 100 parts by weight of elastomer, the alumina trihydrate is present at about 40 to about 200 parts by weight per 100 parts by weight of elastomer, and the iron oxide is present at about 4 to about 10 parts by weight per 100 parts by weight of elastomer. 
     
     
       9. The composition of claim 4, 7 or 8 wherein the halogen containing compound is a chlorinated paraffin and the iron oxide is ferric oxide. 
     
     
       10. The composition of claim 4, 7 or 8 wherein the halogen containing compound is a non-polymeric alicyclic chlorine-containing compound and the iron oxide is ferric oxide. 
     
     
       11. The composition of claim 9 wherein the elastomer is styrene-butadiene rubber. 
     
     
       12. The composition of claim 9 wherein the elastomer is natural rubber. 
     
     
       13. The composition of claim 9 wherein the elastomer is a mixture of styrene-butadiene rubber and natural rubber. 
     
     
       14. A flame retarded elastomeric composition comprising: (a) a hydrocarbon conjugated diene elastomer which is a copolymer of a major amount of hydrocarbon conjugated diene and a minor amount of a C 2  to C 8  halogenated monomer;   (b) about 10 to about 700 parts by weight per 100 parts of elastomer of alumina trihydrate; and   (c) about 0.5 to about 100 parts by weight per 100 parts of elastomer of an iron oxide.   
     
     
       15. The composition of claim 14 wherein the halogen containing monomer comprises at least five weight percent of the elastomer. 
     
     
       16. The composition of claim 15 wherein the iron oxide is ferric oxide. 
     
     
       17. The composition of claim 1 wherein the elastomeric composition is in cellular form.